kernel-jbd.h revision 7d4343d0d05ce69e0a72da5ac34eea415d4c789f
1/* 2 * linux/include/linux/jbd.h 3 * 4 * Written by Stephen C. Tweedie <sct@redhat.com> 5 * 6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved 7 * 8 * This file is part of the Linux kernel and is made available under 9 * the terms of the GNU General Public License, version 2, or at your 10 * option, any later version, incorporated herein by reference. 11 * 12 * Definitions for transaction data structures for the buffer cache 13 * filesystem journaling support. 14 */ 15 16#ifndef _LINUX_JBD_H 17#define _LINUX_JBD_H 18 19#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || !defined(__KERNEL__) 20 21/* Allow this file to be included directly into e2fsprogs */ 22#ifndef __KERNEL__ 23#include "jfs_compat.h" 24#define JFS_DEBUG 25#define jfs_debug jbd_debug 26#else 27 28#include <linux/journal-head.h> 29#include <linux/stddef.h> 30#include <asm/semaphore.h> 31#endif 32 33#define journal_oom_retry 1 34 35#ifdef __STDC__ 36#ifdef CONFIG_JBD_DEBUG 37/* 38 * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal 39 * consistency checks. By default we don't do this unless 40 * CONFIG_JBD_DEBUG is on. 41 */ 42#define JBD_EXPENSIVE_CHECKING 43extern int journal_enable_debug; 44 45#define jbd_debug(n, f, a...) \ 46 do { \ 47 if ((n) <= journal_enable_debug) { \ 48 printk (KERN_DEBUG "(%s, %d): %s: ", \ 49 __FILE__, __LINE__, __FUNCTION__); \ 50 printk (f, ## a); \ 51 } \ 52 } while (0) 53#else 54#define jbd_debug(f, a...) /**/ 55#endif 56#else 57#define jbd_debug(x) /* AIX doesn't do STDC */ 58#endif 59 60extern void * __jbd_kmalloc (char *where, size_t size, int flags, int retry); 61#define jbd_kmalloc(size, flags) \ 62 __jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry) 63#define jbd_rep_kmalloc(size, flags) \ 64 __jbd_kmalloc(__FUNCTION__, (size), (flags), 1) 65 66#define JFS_MIN_JOURNAL_BLOCKS 1024 67 68#ifdef __KERNEL__ 69typedef struct handle_s handle_t; /* Atomic operation type */ 70typedef struct journal_s journal_t; /* Journal control structure */ 71#endif 72 73/* 74 * Internal structures used by the logging mechanism: 75 */ 76 77#define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 78 79/* 80 * On-disk structures 81 */ 82 83/* 84 * Descriptor block types: 85 */ 86 87#define JFS_DESCRIPTOR_BLOCK 1 88#define JFS_COMMIT_BLOCK 2 89#define JFS_SUPERBLOCK_V1 3 90#define JFS_SUPERBLOCK_V2 4 91#define JFS_REVOKE_BLOCK 5 92 93/* 94 * Standard header for all descriptor blocks: 95 */ 96typedef struct journal_header_s 97{ 98 __u32 h_magic; 99 __u32 h_blocktype; 100 __u32 h_sequence; 101} journal_header_t; 102 103 104/* 105 * The block tag: used to describe a single buffer in the journal 106 */ 107typedef struct journal_block_tag_s 108{ 109 __u32 t_blocknr; /* The on-disk block number */ 110 __u32 t_flags; /* See below */ 111} journal_block_tag_t; 112 113/* 114 * The revoke descriptor: used on disk to describe a series of blocks to 115 * be revoked from the log 116 */ 117typedef struct journal_revoke_header_s 118{ 119 journal_header_t r_header; 120 int r_count; /* Count of bytes used in the block */ 121} journal_revoke_header_t; 122 123 124/* Definitions for the journal tag flags word: */ 125#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */ 126#define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 127#define JFS_FLAG_DELETED 4 /* block deleted by this transaction */ 128#define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 129 130 131/* 132 * The journal superblock. All fields are in big-endian byte order. 133 */ 134typedef struct journal_superblock_s 135{ 136/* 0x0000 */ 137 journal_header_t s_header; 138 139/* 0x000C */ 140 /* Static information describing the journal */ 141 __u32 s_blocksize; /* journal device blocksize */ 142 __u32 s_maxlen; /* total blocks in journal file */ 143 __u32 s_first; /* first block of log information */ 144 145/* 0x0018 */ 146 /* Dynamic information describing the current state of the log */ 147 __u32 s_sequence; /* first commit ID expected in log */ 148 __u32 s_start; /* blocknr of start of log */ 149 150/* 0x0020 */ 151 /* Error value, as set by journal_abort(). */ 152 __s32 s_errno; 153 154/* 0x0024 */ 155 /* Remaining fields are only valid in a version-2 superblock */ 156 __u32 s_feature_compat; /* compatible feature set */ 157 __u32 s_feature_incompat; /* incompatible feature set */ 158 __u32 s_feature_ro_compat; /* readonly-compatible feature set */ 159/* 0x0030 */ 160 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 161 162/* 0x0040 */ 163 __u32 s_nr_users; /* Nr of filesystems sharing log */ 164 165 __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 166 167/* 0x0048 */ 168 __u32 s_max_transaction; /* Limit of journal blocks per trans.*/ 169 __u32 s_max_trans_data; /* Limit of data blocks per trans. */ 170 171/* 0x0050 */ 172 __u32 s_padding[44]; 173 174/* 0x0100 */ 175 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 176/* 0x0400 */ 177} journal_superblock_t; 178 179#define JFS_HAS_COMPAT_FEATURE(j,mask) \ 180 ((j)->j_format_version >= 2 && \ 181 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 182#define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \ 183 ((j)->j_format_version >= 2 && \ 184 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 185#define JFS_HAS_INCOMPAT_FEATURE(j,mask) \ 186 ((j)->j_format_version >= 2 && \ 187 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 188 189#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001 190 191/* Features known to this kernel version: */ 192#define JFS_KNOWN_COMPAT_FEATURES 0 193#define JFS_KNOWN_ROCOMPAT_FEATURES 0 194#define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE 195 196#ifdef __KERNEL__ 197 198#include <linux/fs.h> 199#include <linux/sched.h> 200 201#define JBD_ASSERTIONS 202#ifdef JBD_ASSERTIONS 203#define J_ASSERT(assert) \ 204do { \ 205 if (!(assert)) { \ 206 printk (KERN_EMERG \ 207 "Assertion failure in %s() at %s:%d: \"%s\"\n", \ 208 __FUNCTION__, __FILE__, __LINE__, # assert); \ 209 BUG(); \ 210 } \ 211} while (0) 212 213#if defined(CONFIG_BUFFER_DEBUG) 214void buffer_assertion_failure(struct buffer_head *bh); 215#define J_ASSERT_BH(bh, expr) \ 216 do { \ 217 if (!(expr)) \ 218 buffer_assertion_failure(bh); \ 219 J_ASSERT(expr); \ 220 } while (0) 221#define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) 222#else 223#define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 224#define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 225#endif 226 227#else 228#define J_ASSERT(assert) 229#endif /* JBD_ASSERTIONS */ 230 231enum jbd_state_bits { 232 BH_JWrite 233 = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */ 234 BH_Freed, /* 1 if buffer has been freed (truncated) */ 235 BH_Revoked, /* 1 if buffer has been revoked from the log */ 236 BH_RevokeValid, /* 1 if buffer revoked flag is valid */ 237 BH_JBDDirty, /* 1 if buffer is dirty but journaled */ 238}; 239 240/* Return true if the buffer is one which JBD is managing */ 241static inline int buffer_jbd(struct buffer_head *bh) 242{ 243 return __buffer_state(bh, JBD); 244} 245 246static inline struct buffer_head *jh2bh(struct journal_head *jh) 247{ 248 return jh->b_bh; 249} 250 251static inline struct journal_head *bh2jh(struct buffer_head *bh) 252{ 253 return bh->b_private; 254} 255 256struct jbd_revoke_table_s; 257 258/* The handle_t type represents a single atomic update being performed 259 * by some process. All filesystem modifications made by the process go 260 * through this handle. Recursive operations (such as quota operations) 261 * are gathered into a single update. 262 * 263 * The buffer credits field is used to account for journaled buffers 264 * being modified by the running process. To ensure that there is 265 * enough log space for all outstanding operations, we need to limit the 266 * number of outstanding buffers possible at any time. When the 267 * operation completes, any buffer credits not used are credited back to 268 * the transaction, so that at all times we know how many buffers the 269 * outstanding updates on a transaction might possibly touch. */ 270 271struct handle_s 272{ 273 /* Which compound transaction is this update a part of? */ 274 transaction_t * h_transaction; 275 276 /* Number of remaining buffers we are allowed to dirty: */ 277 int h_buffer_credits; 278 279 /* Reference count on this handle */ 280 int h_ref; 281 282 /* Field for caller's use to track errors through large fs 283 operations */ 284 int h_err; 285 286 /* Flags */ 287 unsigned int h_sync: 1; /* sync-on-close */ 288 unsigned int h_jdata: 1; /* force data journaling */ 289 unsigned int h_aborted: 1; /* fatal error on handle */ 290}; 291 292 293/* The transaction_t type is the guts of the journaling mechanism. It 294 * tracks a compound transaction through its various states: 295 * 296 * RUNNING: accepting new updates 297 * LOCKED: Updates still running but we don't accept new ones 298 * RUNDOWN: Updates are tidying up but have finished requesting 299 * new buffers to modify (state not used for now) 300 * FLUSH: All updates complete, but we are still writing to disk 301 * COMMIT: All data on disk, writing commit record 302 * FINISHED: We still have to keep the transaction for checkpointing. 303 * 304 * The transaction keeps track of all of the buffers modified by a 305 * running transaction, and all of the buffers committed but not yet 306 * flushed to home for finished transactions. 307 */ 308 309struct transaction_s 310{ 311 /* Pointer to the journal for this transaction. */ 312 journal_t * t_journal; 313 314 /* Sequence number for this transaction */ 315 tid_t t_tid; 316 317 /* Transaction's current state */ 318 enum { 319 T_RUNNING, 320 T_LOCKED, 321 T_RUNDOWN, 322 T_FLUSH, 323 T_COMMIT, 324 T_FINISHED 325 } t_state; 326 327 /* Where in the log does this transaction's commit start? */ 328 unsigned long t_log_start; 329 330 /* Doubly-linked circular list of all inodes owned by this 331 transaction */ /* AKPM: unused */ 332 struct inode * t_ilist; 333 334 /* Number of buffers on the t_buffers list */ 335 int t_nr_buffers; 336 337 /* Doubly-linked circular list of all buffers reserved but not 338 yet modified by this transaction */ 339 struct journal_head * t_reserved_list; 340 341 /* Doubly-linked circular list of all metadata buffers owned by this 342 transaction */ 343 struct journal_head * t_buffers; 344 345 /* 346 * Doubly-linked circular list of all data buffers still to be 347 * flushed before this transaction can be committed. 348 * Protected by journal_datalist_lock. 349 */ 350 struct journal_head * t_sync_datalist; 351 352 /* 353 * Doubly-linked circular list of all writepage data buffers 354 * still to be written before this transaction can be committed. 355 * Protected by journal_datalist_lock. 356 */ 357 struct journal_head * t_async_datalist; 358 359 /* Doubly-linked circular list of all forget buffers (superceded 360 buffers which we can un-checkpoint once this transaction 361 commits) */ 362 struct journal_head * t_forget; 363 364 /* 365 * Doubly-linked circular list of all buffers still to be 366 * flushed before this transaction can be checkpointed. 367 */ 368 /* Protected by journal_datalist_lock */ 369 struct journal_head * t_checkpoint_list; 370 371 /* Doubly-linked circular list of temporary buffers currently 372 undergoing IO in the log */ 373 struct journal_head * t_iobuf_list; 374 375 /* Doubly-linked circular list of metadata buffers being 376 shadowed by log IO. The IO buffers on the iobuf list and the 377 shadow buffers on this list match each other one for one at 378 all times. */ 379 struct journal_head * t_shadow_list; 380 381 /* Doubly-linked circular list of control buffers being written 382 to the log. */ 383 struct journal_head * t_log_list; 384 385 /* Number of outstanding updates running on this transaction */ 386 int t_updates; 387 388 /* Number of buffers reserved for use by all handles in this 389 * transaction handle but not yet modified. */ 390 int t_outstanding_credits; 391 392 /* 393 * Forward and backward links for the circular list of all 394 * transactions awaiting checkpoint. 395 */ 396 /* Protected by journal_datalist_lock */ 397 transaction_t *t_cpnext, *t_cpprev; 398 399 /* When will the transaction expire (become due for commit), in 400 * jiffies ? */ 401 unsigned long t_expires; 402 403 /* How many handles used this transaction? */ 404 int t_handle_count; 405}; 406 407 408/* The journal_t maintains all of the journaling state information for a 409 * single filesystem. It is linked to from the fs superblock structure. 410 * 411 * We use the journal_t to keep track of all outstanding transaction 412 * activity on the filesystem, and to manage the state of the log 413 * writing process. */ 414 415struct journal_s 416{ 417 /* General journaling state flags */ 418 unsigned long j_flags; 419 420 /* Is there an outstanding uncleared error on the journal (from 421 * a prior abort)? */ 422 int j_errno; 423 424 /* The superblock buffer */ 425 struct buffer_head * j_sb_buffer; 426 journal_superblock_t * j_superblock; 427 428 /* Version of the superblock format */ 429 int j_format_version; 430 431 /* Number of processes waiting to create a barrier lock */ 432 int j_barrier_count; 433 434 /* The barrier lock itself */ 435 struct semaphore j_barrier; 436 437 /* Transactions: The current running transaction... */ 438 transaction_t * j_running_transaction; 439 440 /* ... the transaction we are pushing to disk ... */ 441 transaction_t * j_committing_transaction; 442 443 /* ... and a linked circular list of all transactions waiting 444 * for checkpointing. */ 445 /* Protected by journal_datalist_lock */ 446 transaction_t * j_checkpoint_transactions; 447 448 /* Wait queue for waiting for a locked transaction to start 449 committing, or for a barrier lock to be released */ 450 wait_queue_head_t j_wait_transaction_locked; 451 452 /* Wait queue for waiting for checkpointing to complete */ 453 wait_queue_head_t j_wait_logspace; 454 455 /* Wait queue for waiting for commit to complete */ 456 wait_queue_head_t j_wait_done_commit; 457 458 /* Wait queue to trigger checkpointing */ 459 wait_queue_head_t j_wait_checkpoint; 460 461 /* Wait queue to trigger commit */ 462 wait_queue_head_t j_wait_commit; 463 464 /* Wait queue to wait for updates to complete */ 465 wait_queue_head_t j_wait_updates; 466 467 /* Semaphore for locking against concurrent checkpoints */ 468 struct semaphore j_checkpoint_sem; 469 470 /* The main journal lock, used by lock_journal() */ 471 struct semaphore j_sem; 472 473 /* Journal head: identifies the first unused block in the journal. */ 474 unsigned long j_head; 475 476 /* Journal tail: identifies the oldest still-used block in the 477 * journal. */ 478 unsigned long j_tail; 479 480 /* Journal free: how many free blocks are there in the journal? */ 481 unsigned long j_free; 482 483 /* Journal start and end: the block numbers of the first usable 484 * block and one beyond the last usable block in the journal. */ 485 unsigned long j_first, j_last; 486 487 /* Device, blocksize and starting block offset for the location 488 * where we store the journal. */ 489 kdev_t j_dev; 490 int j_blocksize; 491 unsigned int j_blk_offset; 492 493 /* Device which holds the client fs. For internal journal this 494 * will be equal to j_dev. */ 495 kdev_t j_fs_dev; 496 497 /* Total maximum capacity of the journal region on disk. */ 498 unsigned int j_maxlen; 499 500 /* Optional inode where we store the journal. If present, all 501 * journal block numbers are mapped into this inode via 502 * bmap(). */ 503 struct inode * j_inode; 504 505 /* Sequence number of the oldest transaction in the log */ 506 tid_t j_tail_sequence; 507 /* Sequence number of the next transaction to grant */ 508 tid_t j_transaction_sequence; 509 /* Sequence number of the most recently committed transaction */ 510 tid_t j_commit_sequence; 511 /* Sequence number of the most recent transaction wanting commit */ 512 tid_t j_commit_request; 513 514 /* Journal uuid: identifies the object (filesystem, LVM volume 515 * etc) backed by this journal. This will eventually be 516 * replaced by an array of uuids, allowing us to index multiple 517 * devices within a single journal and to perform atomic updates 518 * across them. */ 519 520 __u8 j_uuid[16]; 521 522 /* Pointer to the current commit thread for this journal */ 523 struct task_struct * j_task; 524 525 /* Maximum number of metadata buffers to allow in a single 526 * compound commit transaction */ 527 int j_max_transaction_buffers; 528 529 /* What is the maximum transaction lifetime before we begin a 530 * commit? */ 531 unsigned long j_commit_interval; 532 533 /* The timer used to wakeup the commit thread: */ 534 struct timer_list * j_commit_timer; 535 int j_commit_timer_active; 536 537 /* Link all journals together - system-wide */ 538 struct list_head j_all_journals; 539 540 /* The revoke table: maintains the list of revoked blocks in the 541 current transaction. */ 542 struct jbd_revoke_table_s *j_revoke; 543}; 544 545/* 546 * Journal flag definitions 547 */ 548#define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */ 549#define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */ 550#define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */ 551#define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */ 552#define JFS_LOADED 0x010 /* The journal superblock has been loaded */ 553 554/* 555 * Function declarations for the journaling transaction and buffer 556 * management 557 */ 558 559/* Filing buffers */ 560extern void __journal_unfile_buffer(struct journal_head *); 561extern void journal_unfile_buffer(struct journal_head *); 562extern void __journal_refile_buffer(struct journal_head *); 563extern void journal_refile_buffer(struct journal_head *); 564extern void __journal_file_buffer(struct journal_head *, transaction_t *, int); 565extern void __journal_free_buffer(struct journal_head *bh); 566extern void journal_file_buffer(struct journal_head *, transaction_t *, int); 567extern void __journal_clean_data_list(transaction_t *transaction); 568 569/* Log buffer allocation */ 570extern struct journal_head * journal_get_descriptor_buffer(journal_t *); 571extern unsigned long journal_next_log_block(journal_t *); 572 573/* Commit management */ 574extern void journal_commit_transaction(journal_t *); 575 576/* Checkpoint list management */ 577int __journal_clean_checkpoint_list(journal_t *journal); 578extern void journal_remove_checkpoint(struct journal_head *); 579extern void __journal_remove_checkpoint(struct journal_head *); 580extern void journal_insert_checkpoint(struct journal_head *, transaction_t *); 581extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *); 582 583/* Buffer IO */ 584extern int 585journal_write_metadata_buffer(transaction_t *transaction, 586 struct journal_head *jh_in, 587 struct journal_head **jh_out, 588 int blocknr); 589 590/* Transaction locking */ 591extern void __wait_on_journal (journal_t *); 592 593/* 594 * Journal locking. 595 * 596 * We need to lock the journal during transaction state changes so that 597 * nobody ever tries to take a handle on the running transaction while 598 * we are in the middle of moving it to the commit phase. 599 * 600 * Note that the locking is completely interrupt unsafe. We never touch 601 * journal structures from interrupts. 602 * 603 * In 2.2, the BKL was required for lock_journal. This is no longer 604 * the case. 605 */ 606 607static inline void lock_journal(journal_t *journal) 608{ 609 down(&journal->j_sem); 610} 611 612/* This returns zero if we acquired the semaphore */ 613static inline int try_lock_journal(journal_t * journal) 614{ 615 return down_trylock(&journal->j_sem); 616} 617 618static inline void unlock_journal(journal_t * journal) 619{ 620 up(&journal->j_sem); 621} 622 623 624static inline handle_t *journal_current_handle(void) 625{ 626 return current->journal_info; 627} 628 629/* The journaling code user interface: 630 * 631 * Create and destroy handles 632 * Register buffer modifications against the current transaction. 633 */ 634 635extern handle_t *journal_start(journal_t *, int nblocks); 636extern handle_t *journal_try_start(journal_t *, int nblocks); 637extern int journal_restart (handle_t *, int nblocks); 638extern int journal_extend (handle_t *, int nblocks); 639extern int journal_get_write_access (handle_t *, struct buffer_head *); 640extern int journal_get_create_access (handle_t *, struct buffer_head *); 641extern int journal_get_undo_access (handle_t *, struct buffer_head *); 642extern int journal_dirty_data (handle_t *, 643 struct buffer_head *, int async); 644extern int journal_dirty_metadata (handle_t *, struct buffer_head *); 645extern void journal_release_buffer (handle_t *, struct buffer_head *); 646extern void journal_forget (handle_t *, struct buffer_head *); 647extern void journal_sync_buffer (struct buffer_head *); 648extern int journal_flushpage(journal_t *, struct page *, unsigned long); 649extern int journal_try_to_free_buffers(journal_t *, struct page *, int); 650extern int journal_stop(handle_t *); 651extern int journal_flush (journal_t *); 652 653extern void journal_lock_updates (journal_t *); 654extern void journal_unlock_updates (journal_t *); 655 656extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev, 657 int start, int len, int bsize); 658extern journal_t * journal_init_inode (struct inode *); 659extern int journal_update_format (journal_t *); 660extern int journal_check_used_features 661 (journal_t *, unsigned long, unsigned long, unsigned long); 662extern int journal_check_available_features 663 (journal_t *, unsigned long, unsigned long, unsigned long); 664extern int journal_set_features 665 (journal_t *, unsigned long, unsigned long, unsigned long); 666extern int journal_create (journal_t *); 667extern int journal_load (journal_t *journal); 668extern void journal_destroy (journal_t *); 669extern int journal_recover (journal_t *journal); 670extern int journal_wipe (journal_t *, int); 671extern int journal_skip_recovery (journal_t *); 672extern void journal_update_superblock (journal_t *, int); 673extern void __journal_abort (journal_t *); 674extern void journal_abort (journal_t *, int); 675extern int journal_errno (journal_t *); 676extern void journal_ack_err (journal_t *); 677extern int journal_clear_err (journal_t *); 678extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr); 679extern int journal_force_commit(journal_t *journal); 680 681/* 682 * journal_head management 683 */ 684extern struct journal_head 685 *journal_add_journal_head(struct buffer_head *bh); 686extern void journal_remove_journal_head(struct buffer_head *bh); 687extern void __journal_remove_journal_head(struct buffer_head *bh); 688extern void journal_unlock_journal_head(struct journal_head *jh); 689 690/* Primary revoke support */ 691#define JOURNAL_REVOKE_DEFAULT_HASH 256 692extern int journal_init_revoke(journal_t *, int); 693extern void journal_destroy_revoke_caches(void); 694extern int journal_init_revoke_caches(void); 695 696extern void journal_destroy_revoke(journal_t *); 697extern int journal_revoke (handle_t *, 698 unsigned long, struct buffer_head *); 699extern int journal_cancel_revoke(handle_t *, struct journal_head *); 700extern void journal_write_revoke_records(journal_t *, transaction_t *); 701 702/* Recovery revoke support */ 703extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 704extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 705extern void journal_clear_revoke(journal_t *); 706extern void journal_brelse_array(struct buffer_head *b[], int n); 707 708/* The log thread user interface: 709 * 710 * Request space in the current transaction, and force transaction commit 711 * transitions on demand. 712 */ 713 714extern int log_space_left (journal_t *); /* Called with journal locked */ 715extern tid_t log_start_commit (journal_t *, transaction_t *); 716extern void log_wait_commit (journal_t *, tid_t); 717extern int log_do_checkpoint (journal_t *, int); 718 719extern void log_wait_for_space(journal_t *, int nblocks); 720extern void __journal_drop_transaction(journal_t *, transaction_t *); 721extern int cleanup_journal_tail(journal_t *); 722 723/* Reduce journal memory usage by flushing */ 724extern void shrink_journal_memory(void); 725 726/* Debugging code only: */ 727 728#define jbd_ENOSYS() \ 729do { \ 730 printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \ 731 current->state = TASK_UNINTERRUPTIBLE; \ 732 schedule(); \ 733} while (1) 734 735/* 736 * is_journal_abort 737 * 738 * Simple test wrapper function to test the JFS_ABORT state flag. This 739 * bit, when set, indicates that we have had a fatal error somewhere, 740 * either inside the journaling layer or indicated to us by the client 741 * (eg. ext3), and that we and should not commit any further 742 * transactions. 743 */ 744 745static inline int is_journal_aborted(journal_t *journal) 746{ 747 return journal->j_flags & JFS_ABORT; 748} 749 750static inline int is_handle_aborted(handle_t *handle) 751{ 752 if (handle->h_aborted) 753 return 1; 754 return is_journal_aborted(handle->h_transaction->t_journal); 755} 756 757static inline void journal_abort_handle(handle_t *handle) 758{ 759 handle->h_aborted = 1; 760} 761 762/* Not all architectures define BUG() */ 763#ifndef BUG 764 #define BUG() do { \ 765 printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \ 766 * ((char *) 0) = 0; \ 767 } while (0) 768#endif /* BUG */ 769 770#else 771 772extern int journal_recover (journal_t *journal); 773extern int journal_skip_recovery (journal_t *); 774 775/* Primary revoke support */ 776extern int journal_init_revoke(journal_t *, int); 777extern void journal_destroy_revoke_caches(void); 778extern int journal_init_revoke_caches(void); 779 780/* Recovery revoke support */ 781extern int journal_set_revoke(journal_t *, unsigned long, tid_t); 782extern int journal_test_revoke(journal_t *, unsigned long, tid_t); 783extern void journal_clear_revoke(journal_t *); 784extern void journal_brelse_array(struct buffer_head *b[], int n); 785 786extern void journal_destroy_revoke(journal_t *); 787#endif /* __KERNEL__ */ 788 789/* Comparison functions for transaction IDs: perform comparisons using 790 * modulo arithmetic so that they work over sequence number wraps. */ 791 792static inline int tid_gt(tid_t x, tid_t y) 793{ 794 int difference = (x - y); 795 return (difference > 0); 796} 797 798static inline int tid_geq(tid_t x, tid_t y) 799{ 800 int difference = (x - y); 801 return (difference >= 0); 802} 803 804extern int journal_blocks_per_page(struct inode *inode); 805 806/* 807 * Definitions which augment the buffer_head layer 808 */ 809 810/* journaling buffer types */ 811#define BJ_None 0 /* Not journaled */ 812#define BJ_SyncData 1 /* Normal data: flush before commit */ 813#define BJ_AsyncData 2 /* writepage data: wait on it before commit */ 814#define BJ_Metadata 3 /* Normal journaled metadata */ 815#define BJ_Forget 4 /* Buffer superceded by this transaction */ 816#define BJ_IO 5 /* Buffer is for temporary IO use */ 817#define BJ_Shadow 6 /* Buffer contents being shadowed to the log */ 818#define BJ_LogCtl 7 /* Buffer contains log descriptors */ 819#define BJ_Reserved 8 /* Buffer is reserved for access by journal */ 820#define BJ_Types 9 821 822extern int jbd_blocks_per_page(struct inode *inode); 823 824#ifdef __KERNEL__ 825 826extern spinlock_t jh_splice_lock; 827/* 828 * Once `expr1' has been found true, take jh_splice_lock 829 * and then reevaluate everything. 830 */ 831#define SPLICE_LOCK(expr1, expr2) \ 832 ({ \ 833 int ret = (expr1); \ 834 if (ret) { \ 835 spin_lock(&jh_splice_lock); \ 836 ret = (expr1) && (expr2); \ 837 spin_unlock(&jh_splice_lock); \ 838 } \ 839 ret; \ 840 }) 841 842/* 843 * A number of buffer state predicates. They test for 844 * buffer_jbd() because they are used in core kernel code. 845 * 846 * These will be racy on SMP unless we're *sure* that the 847 * buffer won't be detached from the journalling system 848 * in parallel. 849 */ 850 851/* Return true if the buffer is on journal list `list' */ 852static inline int buffer_jlist_eq(struct buffer_head *bh, int list) 853{ 854 return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list); 855} 856 857/* Return true if this bufer is dirty wrt the journal */ 858static inline int buffer_jdirty(struct buffer_head *bh) 859{ 860 return buffer_jbd(bh) && __buffer_state(bh, JBDDirty); 861} 862 863/* Return true if it's a data buffer which journalling is managing */ 864static inline int buffer_jbd_data(struct buffer_head *bh) 865{ 866 return SPLICE_LOCK(buffer_jbd(bh), 867 bh2jh(bh)->b_jlist == BJ_SyncData || 868 bh2jh(bh)->b_jlist == BJ_AsyncData); 869} 870 871#ifdef CONFIG_SMP 872#define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock)) 873#else 874#define assert_spin_locked(lock) do {} while(0) 875#endif 876 877#define buffer_trace_init(bh) do {} while (0) 878#define print_buffer_fields(bh) do {} while (0) 879#define print_buffer_trace(bh) do {} while (0) 880#define BUFFER_TRACE(bh, info) do {} while (0) 881#define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 882#define JBUFFER_TRACE(jh, info) do {} while (0) 883 884#endif /* __KERNEL__ */ 885 886#endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */ 887 888/* 889 * Compatibility no-ops which allow the kernel to compile without CONFIG_JBD 890 * go here. 891 */ 892 893#if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE)) 894 895#define J_ASSERT(expr) do {} while (0) 896#define J_ASSERT_BH(bh, expr) do {} while (0) 897#define buffer_jbd(bh) 0 898#define buffer_jlist_eq(bh, val) 0 899#define journal_buffer_journal_lru(bh) 0 900 901#endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */ 902#endif /* _LINUX_JBD_H */ 903